Mainboard compatible with common mode inductor and resistor
The motherboard design with disconnect pads on inductance-resistance compatible welding positions addresses the cost and compatibility issues of using 0-ohm resistors by forming equivalent resistors through solder paste, enhancing EMC compliance and reducing costs.
Patent Information
- Application Number
- CN202420138194.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-19
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-01-19
AI Technical Summary
The use of 0-ohm resistors to replace common-mode inductors on motherboards increases costs due to the need for multiple resistors, and existing pads for inductors and resistors are not compatible, affecting EMC testing and component compatibility.
A motherboard design with inductance-resistance compatible welding positions, including disconnect pads that control connection states based on EMC test results, allowing for the equivalent formation of 0-ohm resistors through solder paste application without actual welding, thus reducing the need for physical resistors.
Saves resistor costs and ensures compatibility by dynamically controlling pad connections based on EMC test results, allowing for efficient use of common-mode inductors and resistors without the need for additional resistors.
Smart Images
Figure CN222192646U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of electronic technology, in particular to a mainboard compatible with common mode inductors and resistors. Background Art
[0002] Electronic products need to undergo EMC testing before leaving the factory. EMC testing is a comprehensive assessment of the electromagnetic interference (EMI) and anti-interference ability (EMS) of electronic products. In order to pass the EMC test, welding positions for common-mode inductors and 0-ohm resistors are usually reserved on the motherboard, on the high-speed signal interface (such as USB2.0 interface, USB3.0 interface, HDMI interface, DP interface, LVDS interface, TYPE-C interface, EDP interface, etc.) and the connection line between the main control and near the interface. If the corresponding interface cannot pass the EMC test, a common-mode inductor is welded on the welding position. If the interface can pass the EMC test, a 0-ohm resistor is used to replace the common-mode inductor.
[0003] like Figure 1 As shown, the top is the pad for the 0-ohm resistor, and the middle is the pad for the common-mode inductor. The structures of the pads of the common-mode inductor and the 0-ohm resistor are different. In order to be compatible, the compatible pads at the bottom are designed. One common-mode inductor or two 0-ohm resistors can be soldered on one soldering position; and a motherboard requires about 30 common-mode inductors. If 0-ohm resistors are used to replace common-mode inductors, 60 0-ohm resistors are required, which will inevitably increase the cost. Utility Model Content
[0004] In response to the above technical problems, an embodiment of the utility model provides a motherboard compatible with common-mode inductors and resistors, which can control the disconnection state of corresponding pads according to EMC test results, meet different upper component connection requirements, and achieve compatibility with common-mode inductors and resistors.
[0005] The utility model embodiment provides a mainboard compatible with common-mode inductance and resistance, including a mainboard body, on which a main control module and an interface are provided, wherein the mainboard body is also provided with a plurality of inductance-resistance compatible welding positions, and the inductance-resistance compatible welding positions include a first pad, a second pad, a third pad, a fourth pad, a first disconnect pad, and a second disconnect pad; one end of the first pad and the second pad is connected to the main control module, one end of the third pad and the fourth pad is connected to the interface, the other end of the first pad is connected to the other end of the third pad through the first disconnect pad, and the other end of the second pad is connected to the other end of the fourth pad through the second disconnect pad;
[0006] The first disconnect pad controls the disconnect state between the first pad and the third pad according to the EMC test result, and the second disconnect pad controls the disconnect state between the second pad and the fourth pad according to the EMC test result.
[0007] Optionally, in the motherboard compatible with the common-mode inductor and resistor, when the EMC test result is passed, the solder paste during printing connects the first disconnect pad itself, so that the first pad is connected to the third pad; the second disconnect pad is connected itself, so that the second pad is connected to the fourth pad; the first pad, the first disconnect pad and the third pad are combined to form a 0 ohm resistor; the third pad, the second disconnect pad and the third-fourth pad are combined to form a 0 ohm resistor.
[0008] Optionally, in the mainboard compatible with the common-mode inductor and resistor, the first disconnect pad includes a first conductive copper foil and a second conductive copper foil, a gap is provided between the first conductive copper foil and the second conductive copper foil, the first conductive copper foil is connected to the other end of the first pad through a trace, and the second conductive copper foil is connected to the other end of the third pad through a trace.
[0009] Optionally, in the mainboard compatible with the common-mode inductor and resistor, the gap is in the shape of a strip bent vertically and horizontally.
[0010] Optionally, in the mainboard in which the common-mode inductor and resistor are compatible, the width of the gap is 0.076 mm.
[0011] Optionally, in the mainboard compatible with the common-mode inductor and resistor, the width and length dimensions of the first to fourth pads are 0.3 mm×0.375 mm.
[0012] Optionally, in the mainboard compatible with the common-mode inductor and resistor, the spacing between each pad and the adjacent conductive copper foil is 0.2 mm.
[0013] The common-mode inductor and resistor compatible mainboard provided by the embodiment of the utility model includes a mainboard body, on which a main control module, an interface and a plurality of inductor-resistor compatible welding positions are provided, and the inductor-resistor compatible welding positions include a first pad, a second pad, a third pad, a fourth pad, a first disconnect pad and a second disconnect pad; one end of the first pad and the second pad is connected to the main control module, one end of the third pad and the fourth pad is connected to the interface, the other end of the first pad is connected to the other end of the third pad through the first disconnect pad, and the other end of the second pad is connected to the other end of the fourth pad through the second disconnect pad; the first disconnect pad controls the disconnection state of the first pad and the third pad according to the EMC test result, and the second disconnect pad controls the disconnection state of the second pad and the fourth pad according to the EMC test result. The disconnection state of the corresponding pad can be controlled according to the EMC test result, so as to meet different upper component connection requirements and realize the compatibility of the common-mode inductor and resistor. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 A diagram of existing compatible pads.
[0015] Figure 2It is a schematic diagram of a motherboard with compatible common-mode inductors and resistors in an embodiment of the present utility model.
[0016] Figure 3 This is a circuit layout diagram of a motherboard with compatible common-mode inductors and resistors in an embodiment of the present utility model. DETAILED DESCRIPTION
[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The embodiments in the utility model and all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0018] See also Figure 2 The common-mode inductor and resistor compatible motherboard provided in the embodiment of the utility model includes a motherboard body, on which a main control module, an interface and a plurality of inductor-resistor compatible welding positions 10 are provided, and the inductor-resistor compatible welding positions 10 are connected between the corresponding pins of the main control module and the interface. The inductor-resistor compatible welding position 10 includes a first pad 11, a second pad 12, a third pad 13, a fourth pad 14, a first disconnect pad 15 and a second disconnect pad 16; one end of the first pad 11 and the second pad 12 are connected to the corresponding pins of the main control module (one end of the first pad 11 is connected to a pin of the main control module, and one end of the second pad 12 is connected to another pin of the main control module), one end of the third pad 13 and one end of the fourth pad 14 are both connected to the corresponding pins of the interface, the other end of the first pad 11 is connected to the other end of the third pad 13 through the first disconnect pad 15, and the other end of the second pad 12 is connected to the other end of the fourth pad 14 through the second disconnect pad 16. The first disconnect pad 15 is used to control the disconnection state between the first pad 11 and the third pad 13 according to the EMC test result, and the second disconnect pad 16 is used to control the disconnection state between the second pad 12 and the fourth pad 14 according to the EMC test result.
[0019] The EMC test results include selecting to weld the common mode inductor when the test fails, and replacing the common mode inductor with a 0 ohm resistor when the test passes. The disconnection state is whether it is disconnected or connected. When welding the common mode inductor, the first disconnect pad 15 disconnects itself, disconnecting the first pad 11 from the third pad 13; the second disconnect pad 16 disconnects itself, disconnecting the second pad 12 from the fourth pad 14; in this way, the pads on the left and right sides are not connected to each other, so as not to affect the use of the common mode inductor.
[0020] When a 0-ohm resistor replaces a common-mode inductor, the 0-ohm resistor is not actually welded, and the state of the 0-ohm resistor is equivalently welded by processing the inductor-resistor compatible welding position 10; at this time, the first disconnect pad 15 is connected to itself through the solder paste during printing, so that the first pad 11 is connected to the third pad 13; the second disconnect pad 16 is connected to itself, so that the second pad 12 is connected to the fourth pad 14; by changing the structure of the existing welding position, the 0-ohm resistor is replaced by the solder paste applied when the mainboard is printed, so that the 0-ohm resistor does not need to be actually welded, which can save the resistor cost and the resistor chip cost.
[0021] In this embodiment, the first disconnect pad 15 and the second disconnect pad 16 have the same structure. Here, the first disconnect pad 15 is taken as an example, which includes a first conductive copper foil 17 and a second conductive copper foil 18. A gap 19 is provided between the first conductive copper foil 17 and the second conductive copper foil 18. The first conductive copper foil 17 is connected to the other end of the first pad 11 through a wiring, and the second conductive copper foil 18 is connected to the other end of the third pad 13 through a wiring. The two conductive copper foils are separated by a gap, so that the first disconnect pad 15 and the second disconnect pad 16 are usually in a default disconnected state, ensuring normal use when welding the common mode inductor. When a 0-ohm resistor is needed to replace the common-mode inductor, the first disconnect pad 15 and the second disconnect pad 16 are not welded with any device, so that when the mainboard is brushed with solder paste, the first pad 11, the third pad 13, the first conductive copper foil 17, the second conductive copper foil 18 and the gap 19 will be covered with solder paste, and then the solder paste on the gap 19 and the solder paste on the conductive copper foil on the left and right sides will automatically be connected together through melting solder after passing through the high temperature of reflow soldering; the first pad 11, the first disconnect pad 15 and the third pad 13 are combined together to form (equivalent to) a 0-ohm resistor. Similarly, the third pad 13, the second disconnect pad 16 and the third and fourth pads 14 are combined together to form a 0-ohm resistor. Equivalent to a 0-ohm resistor, there is no need to purchase an existing 0-ohm resistor and weld it, which greatly saves the cost of resistors.
[0022] When the common-mode inductor is installed, the four pins are respectively soldered to the four pads of the inductor-resistor compatible soldering position 10, and the middle of the inductor-resistor compatible soldering position 10 is disconnected, so as not to affect the use of the common-mode inductor; when a 0 ohm resistor is selected, the two opposite pads of the inductor-resistor compatible soldering position 10 and the middle are connected through solder paste, which is equivalent to two 0 ohm resistors.
[0023] Preferably, the first disconnect pad 15 is a 0.3mm*0.45mm rectangle as a whole, and the gap 19 is a thin strip centered vertically, horizontally, and vertically bent, thereby dividing the rectangle into an L-shaped first conductive copper foil 17 and a second conductive copper foil 18. The maximum width of the gap 19 is 0.076mm, which meets the minimum spacing requirements of the PCB board factory's process capabilities. Such a strip makes it easier for the solder paste on both sides to form a solder ball short-circuited together. Since the area of the conductive copper foil is relatively small, if the gap adopts other shapes, such as a vertical, arc, or wave, it is easy to form two separated solder balls, resulting in failure to short-circuit.
[0024] When a common-mode inductor is soldered on the inductor-resistor compatible soldering position 10, the four pins of the common-mode inductor will only be connected to the four pads, and solder paste will not be applied to the first disconnect pad 15 and the second disconnect pad 16 to ensure that the gap will not be connected to form a resistor due to external interference or other influences.
[0025] Preferably, the size of the first pad 11 to the fourth pad 14 is preferably 0.3mm (the vertical direction in the figure represents the width) * 0.375mm (the horizontal direction in the figure represents the length), and the spacing between each pad and the adjacent conductive copper foil is preferably 0.2mm, which meets the minimum spacing requirement of the PCB board factory's process capability, so that the signal integrity is optimal.
[0026] Figure 3 In the dotted box, four inductor-resistor compatible soldering positions are taken as an example to show the circuit layout of the inductor-resistor compatible soldering positions on the mainboard. This is only an example and can be laid out according to requirements during specific implementation.
[0027] In summary, the common-mode inductor and resistor compatible mainboard provided by the utility model improves the existing compatible pads, and the disconnect pads can control the disconnect state of the corresponding pads according to the EMC test results. When the test passes, the disconnect pads themselves are connected by using the solder paste applied during printing, so that the disconnect pad and the two connected pads are combined to be equivalent to a 0-ohm resistor. There is no need to actually weld the 0-ohm resistor, which can save the resistor cost and the cost of the resistor patch.
[0028] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A motherboard compatible with common mode inductors and resistors, comprising a motherboard body, on which a main control module and an interface are provided, characterized in that: The mainboard body is also provided with a plurality of inductive resistance compatible welding positions, and the inductive resistance compatible welding positions include a first welding pad, a second welding pad, a third welding pad, a fourth welding pad, a first disconnect welding pad, and a second disconnect welding pad; one end of the first welding pad and the second welding pad is connected to the main control module, one end of the third welding pad and the fourth welding pad is connected to the interface, the other end of the first welding pad is connected to the other end of the third welding pad through the first disconnect welding pad, and the other end of the second welding pad is connected to the other end of the fourth welding pad through the second disconnect welding pad; The first disconnect pad controls the disconnect state between the first pad and the third pad according to the EMC test result, and the second disconnect pad controls the disconnect state between the second pad and the fourth pad according to the EMC test result.
2. The motherboard compatible with common mode inductors and resistors according to claim 1, characterized in that: When the EMC test result is passed, the solder paste during printing connects the first disconnect pad itself, so that the first pad is connected to the third pad; the second disconnect pad is connected itself, so that the second pad is connected to the fourth pad; the first pad, the first disconnect pad and the third pad are combined to form a 0 ohm resistor; the third pad, the second disconnect pad and the third and fourth pads are combined to form a 0 ohm resistor.
3. The common mode inductor and resistor compatible motherboard according to claim 1, characterized in that: The first disconnect pad includes a first conductive copper foil and a second conductive copper foil, a gap is provided between the first conductive copper foil and the second conductive copper foil, the first conductive copper foil is connected to the other end of the first pad through a trace, and the second conductive copper foil is connected to the other end of the third pad through a trace.
4. The motherboard compatible with common mode inductors and resistors according to claim 3, characterized in that: The gap is in the shape of a strip that is bent vertically, horizontally, and vertically.
5. The motherboard compatible with common mode inductors and resistors according to claim 4, characterized in that: The width of the gap is 0.076 mm.
6. The common mode inductor and resistor compatible motherboard according to claim 1, characterized in that: The width and length dimensions of the first to fourth pads are 0.3 mm×0.375 mm.
7. The common mode inductor and resistor compatible motherboard according to claim 3, characterized in that: The spacing between each pad and the adjacent conductive copper foil is 0.2 mm.